Margaret Thatcher (1925-2013) was the UK's first female prime minister, serving from 1979 to 1990, and is known for reducing trade union influence and privatizing industries. Despite her controversial policies and a tumultuous political career, including the Falklands War and economic reforms, she became a significant figure in British history, earning the nickname 'the Iron Lady.' Thatcher resigned in 1990 after internal party challenges and passed away in 2013, leaving a lasting impact on British politics.